This invention pertains to a weighing mechanism designed to provide a more accurate weight in less time than present systems. This application is a continuation-in-part of a previous application by the same inventor, Ser. No. 08/334,957, filed Nov. 7, 1994 and now specifically abandoned.
Weighing systems for material suspended from a trolley rolling on a standing rail are fairly common. That material consists usually of meat carcasses, but may also include some other types of material. The purpose is to roll the trolley along the rail by the operation of a chain having a dog to engage the trolley to pull it over a short section of suspended track separated from the rest of the rail. The live trackxe2x80x94that free sectionxe2x80x94is supported by weighing cells of various types. These cells may be strain gage type devices, thus a type of spring device, which provide for a measured displacement of measurable displacement to indicate the weight.
There are a number of problems with such a system. One of the chief of these problems is the oscillation of the free track caused by sudden loading of the spring-like devices which support that part of the track. The carrying trolley typically has only a single load-carrying wheel having linear contact with the track. Thus, any transition from one part of the rail to another is very quick, going from no load to full load almost instantaneously. Such a quick bounce creates an oscillation in the weighing cells making necessary an appreciable time for damping before the weight can be accurately measured.
There is another factor entering into the same problem. That factor is the motor force moving the trolley along the rail. In most instances that force is provided by a chain pulling the trolley along the rail through a dog on the chain engaging, either directly or indirectly through an arm, the top of the trolley. This engagement, particularly when the transition between the regular rail and the live rail is reached, is somewhat jerky resulting in a swinging load on the trolley. Such swinging also contributes to objectionable oscillation in the scale. The contact with the chain may also create a small component of vertical force creating a false reading of the scale.
The swinging problem is worsened by another system sometimes used to advance the trolley. This other system utilizes a downward slope on the live track to cause the trolley to roll. Trolleys in such a system must be freely rolling (well lubricated). Here again, the transition from regular to live rail is very quick so that the bouncing oscillation is enlarged. Swinging may also be encouraged by the slight bump between the two portions of the rails.
It should also be noted that flat or out-of-round wheels can also contribute to a bouncing oscillation.
It is the purpose of the present invention to avoid, so far as possible, any bouncing or swinging of the load as it passes over the live track. This is accomplished by use of a transitional rail to load the live rail more gradually and a unique separate transporting system to move the trolley on the live track. Thus, the bouncing is virtually eliminated and the swinging is reduced. To avoid an uncertain tare weight, the transitional rail is normally kept out of contact with the live rail.